1. Field of the Invention
The present invention relates to a color enlarger for making color photographic prints from original color films.
2. Description of the Prior Art
A prior art color enlarger, manufactured and sold by Burgie Marketing Companies under a trade name, "New-Omega Automatic D-5500 Darkroom System", utilizes a control box separate from an exposure head, but connected electrically therewith so that the exposure and the color balance given by the exposure head can be controlled according to data of exposure amount and color balance set in the control box. This is advantageous in that the data can be set at the location where a photographic paper is placed, and therefore, the color enlarger of the above described type is easier to handle than the type wherein the exposure and color balance adjustment is built in the exposure head.
However, with the above described prior art color enlarger, a procedure to precompute the data of the exposure value and the color balance is performed by the use of an analyzer (an equipment for measuring the light passing through a film to calculate and display the correctness or incorrectness of the color balance as well as the exposure value) which is also a member separate from the control box. Since no signal transmission take place between the color analyzer and the control box, the user of the prior art color enlarger now under discussion is required to change, while looking at the display given by the color analyzer, the exposure value and the color balance determined by the exposure head, the data, which have been set in the control box, being ones applicable to produce the best print when the display given the color analyzer become proper. In other word, the user is required to transfer signals between the color analyzer and the control box, and therefore, much complicated and time-consuming procedures are required.
On the other hand, a color enlarger of a type mainly installed at a developing and printing service station is of a design that can be used by setting data required to produce an acceptable photographic print, measuring the light passing through a film by the use of a so-called nega-color analyzer for measuring and precomputing data for printing work for each film, precomputing a lighting condition for a light emitting unit in correspondence with the data set, storing the precomputed data in a memory means, and controlling the light emitting unit on the basis of the data stored in the memory means. This type of color enlarger is for producing a large number of color prints of equal size and is not, therefore, equipped with capabilities of changing the magnification factor and effecting exposure on the basis of the data set manually in the device (for example, making trial prints). Thus, the color enlarger generally installed at the professional establishment has a problem in that the capabilities or functions it can provide are short of the requirement to be provided in a small-size color enlarger to which the present invention pertains.